[PATCH] NUL terminate the object data in patch_delta()

[PATCH] NUL terminate the object data in patch_delta()

At least pretty_print_commit() expects to get NUL-terminated commit data to
work properly.  unpack_sha1_rest(), which reads objects from separate files,
and unpack_non_delta_entry(), which reads non-delta-compressed objects from
pack files, already add the NUL byte after the object data, but patch_delta()
did not do it, which caused problems with, e.g., git-rev-list --pretty when
there are delta-compressed commit objects.

Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Signed-off-by: Junio C Hamano <junkio@cox.net>